Numerous spectacle designs are currently available, many of which feature frames made entirely of plastic material, or made partly of plastic and partly of metal elements, or made entirely of metal elements; and the lenses are normally supported on a frame fitted tightly about the edge of the entire lens and connected integral with the intermediate bridge.
In such designs, the bridge connecting the lenses presents two plates or nose rests, which rest laterally on either side of the nose to support the spectacles at the front. In some designs, the plates are fixed and formed in one piece with the frame, or are movable and fitted to the bridge by an articulated joint to enable them to adapt and rest comfortably on either side of the nose.
European Patent n. 256.098-B1 relates to a spectacle mount made of metal wire, and comprising two lateral arms pivoting on respective hinges, each of which is in turn connected to the respective lens by a portion of wire bent into a U-shaped bend in a plane, normally vertical, parallel to the fixed pin of the hinge, which bend is designed to be inserted elastically into a corresponding opening or slot formed close to the outer edge of the lens. The intermediate bridge connecting the two lenses, and which is also made of metal wire, is fitted to each lens by a wire portion bent into a U and inserted elastically into an opening formed close to the inner edge of the lens.
Two movable plates for support on either side of the nose are fitted in freely adjustable manner to respective eyelets integral with the connecting bridge and on which the plates are permitted to slide.
The above state-of-the-art mount nevertheless presents several drawbacks. Forming openings large enough to house the two wire portions forming the bend means removing a large amount of material and therefore involves more time and cost. Moreover, since the bend, once inserted inside the opening, works by expanding elastically, the lenses, which are normally made of highly rigid, fragile material of poor tensile strength and are already weakened by milling the openings, are subjected to dangerous tensile stress. To reduce the risk involved, the already large openings are therefore formed closer to the center of the lens, which, besides noticeably invading the field of view, creates discomfort to the wearer, especially in the case of thick lenses, by creating highly noticeable opaque or reflecting walls. Also to be taken into account is the accumulation of soil in the gap between the wires and the opening, which impairs the appearance of the spectacles.
Besides being unsightly, the plates eventually become a source of discomfort with prolonged use, and, by virtue of their shape, are easily soiled, thus further impairing their overall appearance.